Ever since events have been transmitted to and received by devices, such as radios and televisions, people have desired to be able to pause the display of a continuous event at selectable periods. Consider the example of a program being watched on a television and a viewer leaves the room to attend to a phone call. In this case, the display of the program would preferably be interrupted so that the viewer does not miss any of it. Upon returning, it is desirable to be able to resume viewing or listening to the transmitted event from the point at which the viewer left the room.
Also, when watching television, very often the viewer would like to return to a previous period in the continuously transmitted event to review that interval again. This is conventionally possible using a recording, such as a video tape of the event. In this case, the user is able to pause the video tape at any desired time. Then, at any future time the viewer can begin playing the tape again and watch the recorded event starting from the point of time on the tape at which its play back was stopped. Or, if something of interest occurs during the viewing of the recorded event, the viewer can rewind the video tape and watch that interval over and over again. After watching this interesting interval, the viewer can allow the tape to continually play to watch the rest of the event.
However in the case of a transmitted program, such as a movie received by the viewer's television, there is no way in the conventional art to temporarily pause the viewing of the transmitted program at any desired time and then later return to the transmitted program picking up at that point in time when the pause began.
For example, a viewer watching a show may be interrupted by a phone call. Traditionally, the viewer must either ignore the call and continue watching the program, or take the call and miss that interval of the program which coincides with the duration of the phone call. When the viewer returns from the phone call the program has proceeded to a different point in time and the viewer is not able to watch the interval of the program which coincides with the time of the phone call.
Also, there may be two programs being received by the viewer's television of interest to the viewer. In this case, a viewer with a video cassette recorder (VCR) may record one of the shows while viewing the other The viewer can then watch one of the shows as it is being transmitted and at a later time watch the recorded show. However, there is no conventional way for a viewer to temporarily pause from the viewing of one show and switch to the other show to watch an interesting portion thereof then switch back to the first show and resume viewing from the point at the beginning of the pause. Rather, the viewer returns to the first show at a point in time of the first show further along than the point in time of the beginning of the pause. Therefore, the viewer misses that portion of the first show which elapsed during the switch to the other program. A conventional television set allows a viewer to decide what to watch, but not when to watch it. Each television program is broadcasted from a television station, beamed from a satellite or carried over a cable, to each television set in a synchronous manner. Stated otherwise, each television set that is tuned to a particular channel receives the same television program starting and ending at the same times. Those who wish to view a program must synchronize their schedules with the time of the program broadcast. Video tape recorders have become very popular devices because they let a viewer watch a program asynchronously, but only after the program has been aired. That is, a viewer can watch the recorded program at any time he or she desires. A VCR can be programmed to record a certain show on a certain channel at a certain time. A viewer can then view the show at a later time by playing the recorded VCR tape. However, a viewer still must wait until the entire program has been received and recorded before viewing the play back from the VCR tape.
A VCR tape records a video signal in a linear sequential manner that is not randomly addressable. If the portion of the recorded program that is to be replayed is at the end of the tape, the tape must be “fast forwarded” all the way through until the beginning of the desired portion is reached. To play back a particular portion of a recorded program, the VCR tape must be either rewound or fast forwarded to the segment of tape that contains the recorded portion. However, recently recording/play back devices and disk recording media have been developed that allow a video signal to be recorded and played back in a random access manner. To replay a particular portion of a recorded event, the play back head of the recording device can quickly access the location of the disk that contains the information. Thus searching for and retrieving of a particular recorded portion can be much quicker from a disk recording medium as opposed to a tape recording medium. Further, typically the information recorded on a disk is indexed by storing distinguishing information in a file allocation table located on the disk. When a particular set of information is to be retrieved, its location on the disk is found by referencing the file allocation table.
A video signal contains a large amount of information, and thus requires a recording scheme with a large storage capacity to record, for example, a television program in its entirety (as can be done using a conventional VCR). Recently developed video compression technology and recording media now enable a useful amount of video information to be recorded in a random access manner. This recent technology includes MPEG compression, recordable compact disks, magneto-optical disks, phase change optical disks, and the like. Companies such as Sony, Hitachi and 3M are increasing the storage capacity of magneto-optical disks, and Matsushita is making advances in phase change storage technology.
The accepted wisdom in the art is that a video cassette recorder can be used to make a recording of a television show so that the show can be later watched by a viewer in an asynchronous manner, that is, with pauses and replays determined according to the desires of the viewer.
In accordance with the teachings of the prior art, a dual deck recorder can be used to make copies of prerecorded tapes, or possibly record two different shows at once (if two channels can be tuned in), or possibly watch one prerecorded show while taping another.
There is no prior reference that enables a television program to be viewed at a pace dictated by the viewer, even through the television program continues to be aired. No prior device allows a viewer to watch a broadcast television program during the broadcast as if it were a prerecorded tape (with the one exception of fast forwarding through portions of the program that have not yet been received).
The Internet has recently exploded in popularity. Computer users are getting on-line to search for and download their choice of information from the large amount of information content already available. Businesses have realized the commercial prospects of having an on-line presence, and often provide their world wide web site address in print, radio and television advertisements. A computer user with a modem can get on-line and access the business' web site to obtain more information about a particular product that the user is interested in. This form of advertisement will most likely become more and more common as internet use increases. However, the user must memorize or write down the advertiser's web site address, or perform a sometimes labor and time intensive on-line search to find the web site. If a television viewer wishes to access the advertiser's web site for more information, then he or she must wait until after the program has aired if it is desired to watch the whole program. Therefore, there is a need for a time shifting event recorder that allows a viewer to temporarily pause a program, access a computer network such as the Internet, and then resume viewing the program without missing any of it.
The Intel Corporation and others are developing a technology called intercasting, in which world wide web-like pages are distributed to television sets via the vertical blanking interval (VBI). An intercast technology group has been formed by a number of leading companies in the information technology industry. Many cable and broadcast television transmissions are incorporating the intercast or intercast-like technology and including web page-like information along with the television program.
The intercast information is currently either displayed in a split screen, or the display is toggled between the television program and the intercast information. In any event, to make use of the intercast signal the viewer must either miss part of the television program, or try to pay attention to the program while simultaneously concentrating on retrieving and understanding the intercast information. This is one of the major drawbacks of the intercast technology.
On yet another front, it has become cliche that most VCR users have much difficulty in programming their VCRs to record television programs. Even with on-screen programming, and other attempts to demystify the process, most people simply cannot program their VCRs.
On yet another front, there is a need for a device that enables users to enjoy the benefits of the on-line experience via their television. Products are being made available that enable a user to connect with the Internet through a cable or telephone modem and display, for example, world wide web pages on their television. However, these products, such as WebTV from Philips Magnavox and Sony, merely allow the user access to the Internet. They provide no means for pausing the display of a television program according to the user's desires. They also fail to offer the advantages of any of the inventions as will be discussed below.